Mercurial > hg > aboriginal
view sources/patches/linux-noperl-timeconst.patch @ 1376:a6d18adf198d
Added tag 1.0.2 for changeset a9685aea2a2c
| author | Rob Landley <rob@landley.net> |
|---|---|
| date | Tue, 14 Jun 2011 20:48:07 -0500 |
| parents | 1bc0c01950ca |
| children | ddbd48ced0d7 |
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Message-ID: <4D35FEF3.4070001@parallels.com> Date: Tue, 18 Jan 2011 14:58:27 -0600 From: Rob Landley <rlandley@parallels.com> User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20101208 Thunderbird/3.1.7 To: Jesper Juhl <jj@chaosbits.net>, Ingo Molnar <mingo@elte.hu>, "H. Peter Anvin" <hpa@zytor.com>, Yinghai Lu <yinghai@kernel.org>, Tejun Heo <tj@kernel.org>, Don Zickus <dzickus@redhat.com>, <linux-kernel@vger.kernel.org> Subject: Re: [PATCH] Use sed instead of perl to generate x86/kernel/cpu/capflags.c. References: <4D334E1E.7090708@parallels.com> <alpine.LNX.2.00.1101162103450.13377@swampdragon.chaosbits.net> <4D335554.7020403@parallels.com> <alpine.LNX.2.00.1101162136360.13377@swampdragon.chaosbits.net> In-Reply-To: <alpine.LNX.2.00.1101162136360.13377@swampdragon.chaosbits.net> Content-Type: multipart/mixed; boundary="------------070402000802050303040701" MIME-Version: 1.0 --------------070402000802050303040701 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit From: Rob Landley <rlandley@parallels.com> Replace perl header file generator with smaller/faster/simpler C version. Signed-off-by: Rob Landley <rlandley@parallels.com> --- I ran the attached test script to compare the output of the C program with the output of the perl version for every HZ from 1 to 5000 to make sure it was producing the same constants. kernel/Makefile | 10 - kernel/mktimeconst.c | 109 +++++++++++ kernel/timeconst.pl | 378 ----------------------------------------- 3 files changed, 115 insertions(+), 382 deletions(-) diff --git a/kernel/Makefile b/kernel/Makefile index 5669f71..ba9ce6d 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -133,8 +133,10 @@ $(obj)/config_data.h: $(obj)/config_data.gz FORCE $(obj)/time.o: $(obj)/timeconst.h -quiet_cmd_timeconst = TIMEC $@ - cmd_timeconst = $(PERL) $< $(CONFIG_HZ) > $@ +hostprogs-y += mktimeconst +quiet_cmd_mktimeconst = TIMEC $@ + cmd_mktimeconst = $(obj)/mktimeconst $(CONFIG_HZ) $@ || ( rm -f $@ && exit 1 ) + targets += timeconst.h -$(obj)/timeconst.h: $(src)/timeconst.pl FORCE - $(call if_changed,timeconst) +$(obj)/timeconst.h: $(obj)/mktimeconst FORCE + $(call if_changed,mktimeconst) --- /dev/null 2011-01-13 17:00:36.470564274 -0600 +++ b/kernel/mktimeconst.c 2011-01-16 12:44:04.091168778 -0600 @@ -0,0 +1,109 @@ +/* Copyright 2010 Parallels Inc, licensed under GPLv2 */ + +#include <inttypes.h> +#include <stdio.h> +#include <stdlib.h> + +int main(int argc, char *argv[]) +{ + uint64_t hz, periods[] = {1000, 1000000}; + char *names[] = {"MSEC", "USEC"}; + FILE *file; + int i, j; + + if (argc != 3 || (hz = atol(argv[1])) < 1 + || !(file = fopen(argv[2], "w"))) + { + fprintf(stderr, "Usage: mktimeconst HZ FILENAME\n\n"); + fprintf(stderr, "Generate a header file with constants to convert between\n"); + fprintf(stderr, "decimal HZ timer ticks and milisecond or microsecond delays,\n"); + fprintf(stderr, "using reciprocal multiplication to avoid 64 bit division.\n"); + exit(1); + } + + fprintf(file, + "/* Automatically generated by kernel/mktimeconst */\n" + "/* Conversion constants for HZ == %"PRIu64" */\n\n" + "#ifndef __KERNEL_TIMECONST_H\n" + "#define __KERNEL_TIMECONST_H\n\n" + "#include <linux/param.h>\n" + "#include <linux/types.h>\n\n" + "#if HZ != %"PRIu64"\n" + "#error \"kernel/timeconst.h has the wrong HZ value!\"\n" + "#endif\n\n", hz, hz); + + /* Repeat for MSEC and USEC */ + + for (i = 0; i < 2; i++) { + uint64_t gcd, period; + + /* Find greatest common denominator using Euclid's algorithm. */ + + gcd = hz; + period = periods[i]; + while (period) { + uint64_t temp = gcd % period; + gcd = period; + period = temp; + } + + /* Output both directions (HZ_TO_PERIOD and PERIOD_TO_HZ) */ + + for (j = 0; j < 2; j++) { + char name[16]; + uint64_t from = j ? periods[i] : hz; + uint64_t to = j ? hz : periods[i]; + uint64_t mul32 = 0, adj32 = 0, shift = 0; + + sprintf(name, j ? "%s_TO_HZ" : "HZ_TO_%s", names[i]); + + /* Figure out what shift value gives 32 significant + bits of MUL32 data. (Worst case to=1 from=1000000 + uses 52 bits, to<<shift won't overflow 64 bit math.) + */ + + for (;;) { + mul32 = ((to << shift) + from - 1) / from; + if (mul32 >= (1L<<31)) + break; + shift++; + } + + /* ADJ32 is is just (((FROM/GCD)-1)<<SHIFT)/(FROM/GCD) + but this can overflow 64 bit math (examples, HZ=24 + or HZ=122). Worst case scenario uses 32+20+20=72 + bits. Workaround: split off bottom 32 bits and + reassemble after calculation (32+64=96 bits). */ + + adj32 = from / gcd; + + if (shift > 32) { + uint64_t upper, lower; + + upper = (adj32 - 1) << (shift - 32); + lower = (upper % adj32) << 32; + adj32 = ((upper/adj32) << 32) + (lower/adj32); + } else + adj32 = ((adj32 - 1) << shift) / adj32; + + /* Emit the constants into the header file. */ + + fprintf(file, "#define %s_MUL32\tU64_C(0x%"PRIx64")\n", + name, mul32); + fprintf(file, "#define %s_ADJ32\tU64_C(0x%"PRIx64")\n", + name, adj32); + fprintf(file, "#define %s_SHR32\t%"PRIu64"\n", + name, shift); + fprintf(file, "#define %s_NUM\t\tU64_C(%"PRIu64")\n", + name, to/gcd); + fprintf(file, "#define %s_DEN\t\tU64_C(%"PRIu64")\n\n", + name, from/gcd); + } + } + fprintf(file, "#endif /* __KERNEL_TIMECONST_H */\n"); + + /* Notice if the disk fills up. */ + + fflush(stdout); + return ferror(stdout); +} --- a/kernel/timeconst.pl 2010-12-19 11:33:53.969732934 -0600 +++ /dev/null 2011-01-13 17:00:36.470564274 -0600 @@ -1,378 +0,0 @@ -#!/usr/bin/perl -# ----------------------------------------------------------------------- -# -# Copyright 2007-2008 rPath, Inc. - All Rights Reserved -# -# This file is part of the Linux kernel, and is made available under -# the terms of the GNU General Public License version 2 or (at your -# option) any later version; incorporated herein by reference. -# -# ----------------------------------------------------------------------- -# - -# -# Usage: timeconst.pl HZ > timeconst.h -# - -# Precomputed values for systems without Math::BigInt -# Generated by: -# timeconst.pl --can 24 32 48 64 100 122 128 200 250 256 300 512 1000 1024 1200 -%canned_values = ( - 24 => [ - '0xa6aaaaab','0x2aaaaaa',26, - 125,3, - '0xc49ba5e4','0x1fbe76c8b4',37, - 3,125, - '0xa2c2aaab','0xaaaa',16, - 125000,3, - '0xc9539b89','0x7fffbce4217d',47, - 3,125000, - ], 32 => [ - '0xfa000000','0x6000000',27, - 125,4, - '0x83126e98','0xfdf3b645a',36, - 4,125, - '0xf4240000','0x0',17, - 31250,1, - '0x8637bd06','0x3fff79c842fa',46, - 1,31250, - ], 48 => [ - '0xa6aaaaab','0x6aaaaaa',27, - 125,6, - '0xc49ba5e4','0xfdf3b645a',36, - 6,125, - '0xa2c2aaab','0x15555',17, - 62500,3, - '0xc9539b89','0x3fffbce4217d',46, - 3,62500, - ], 64 => [ - '0xfa000000','0xe000000',28, - 125,8, - '0x83126e98','0x7ef9db22d',35, - 8,125, - '0xf4240000','0x0',18, - 15625,1, - '0x8637bd06','0x1fff79c842fa',45, - 1,15625, - ], 100 => [ - '0xa0000000','0x0',28, - 10,1, - '0xcccccccd','0x733333333',35, - 1,10, - '0x9c400000','0x0',18, - 10000,1, - '0xd1b71759','0x1fff2e48e8a7',45, - 1,10000, - ], 122 => [ - '0x8325c53f','0xfbcda3a',28, - 500,61, - '0xf9db22d1','0x7fbe76c8b',35, - 61,500, - '0x8012e2a0','0x3ef36',18, - 500000,61, - '0xffda4053','0x1ffffbce4217',45, - 61,500000, - ], 128 => [ - '0xfa000000','0x1e000000',29, - 125,16, - '0x83126e98','0x3f7ced916',34, - 16,125, - '0xf4240000','0x40000',19, - 15625,2, - '0x8637bd06','0xfffbce4217d',44, - 2,15625, - ], 200 => [ - '0xa0000000','0x0',29, - 5,1, - '0xcccccccd','0x333333333',34, - 1,5, - '0x9c400000','0x0',19, - 5000,1, - '0xd1b71759','0xfff2e48e8a7',44, - 1,5000, - ], 250 => [ - '0x80000000','0x0',29, - 4,1, - '0x80000000','0x180000000',33, - 1,4, - '0xfa000000','0x0',20, - 4000,1, - '0x83126e98','0x7ff7ced9168',43, - 1,4000, - ], 256 => [ - '0xfa000000','0x3e000000',30, - 125,32, - '0x83126e98','0x1fbe76c8b',33, - 32,125, - '0xf4240000','0xc0000',20, - 15625,4, - '0x8637bd06','0x7ffde7210be',43, - 4,15625, - ], 300 => [ - '0xd5555556','0x2aaaaaaa',30, - 10,3, - '0x9999999a','0x1cccccccc',33, - 3,10, - '0xd0555556','0xaaaaa',20, - 10000,3, - '0x9d495183','0x7ffcb923a29',43, - 3,10000, - ], 512 => [ - '0xfa000000','0x7e000000',31, - 125,64, - '0x83126e98','0xfdf3b645',32, - 64,125, - '0xf4240000','0x1c0000',21, - 15625,8, - '0x8637bd06','0x3ffef39085f',42, - 8,15625, - ], 1000 => [ - '0x80000000','0x0',31, - 1,1, - '0x80000000','0x0',31, - 1,1, - '0xfa000000','0x0',22, - 1000,1, - '0x83126e98','0x1ff7ced9168',41, - 1,1000, - ], 1024 => [ - '0xfa000000','0xfe000000',32, - 125,128, - '0x83126e98','0x7ef9db22',31, - 128,125, - '0xf4240000','0x3c0000',22, - 15625,16, - '0x8637bd06','0x1fff79c842f',41, - 16,15625, - ], 1200 => [ - '0xd5555556','0xd5555555',32, - 5,6, - '0x9999999a','0x66666666',31, - 6,5, - '0xd0555556','0x2aaaaa',22, - 2500,3, - '0x9d495183','0x1ffcb923a29',41, - 3,2500, - ] -); - -$has_bigint = eval 'use Math::BigInt qw(bgcd); 1;'; - -sub bint($) -{ - my($x) = @_; - return Math::BigInt->new($x); -} - -# -# Constants for division by reciprocal multiplication. -# (bits, numerator, denominator) -# -sub fmul($$$) -{ - my ($b,$n,$d) = @_; - - $n = bint($n); - $d = bint($d); - - return scalar (($n << $b)+$d-bint(1))/$d; -} - -sub fadj($$$) -{ - my($b,$n,$d) = @_; - - $n = bint($n); - $d = bint($d); - - $d = $d/bgcd($n, $d); - return scalar (($d-bint(1)) << $b)/$d; -} - -sub fmuls($$$) { - my($b,$n,$d) = @_; - my($s,$m); - my($thres) = bint(1) << ($b-1); - - $n = bint($n); - $d = bint($d); - - for ($s = 0; 1; $s++) { - $m = fmul($s,$n,$d); - return $s if ($m >= $thres); - } - return 0; -} - -# Generate a hex value if the result fits in 64 bits; -# otherwise skip. -sub bignum_hex($) { - my($x) = @_; - my $s = $x->as_hex(); - - return (length($s) > 18) ? undef : $s; -} - -# Provides mul, adj, and shr factors for a specific -# (bit, time, hz) combination -sub muladj($$$) { - my($b, $t, $hz) = @_; - my $s = fmuls($b, $t, $hz); - my $m = fmul($s, $t, $hz); - my $a = fadj($s, $t, $hz); - return (bignum_hex($m), bignum_hex($a), $s); -} - -# Provides numerator, denominator values -sub numden($$) { - my($n, $d) = @_; - my $g = bgcd($n, $d); - return ($n/$g, $d/$g); -} - -# All values for a specific (time, hz) combo -sub conversions($$) { - my ($t, $hz) = @_; - my @val = (); - - # HZ_TO_xx - push(@val, muladj(32, $t, $hz)); - push(@val, numden($t, $hz)); - - # xx_TO_HZ - push(@val, muladj(32, $hz, $t)); - push(@val, numden($hz, $t)); - - return @val; -} - -sub compute_values($) { - my($hz) = @_; - my @val = (); - my $s, $m, $a, $g; - - if (!$has_bigint) { - die "$0: HZ == $hz not canned and ". - "Math::BigInt not available\n"; - } - - # MSEC conversions - push(@val, conversions(1000, $hz)); - - # USEC conversions - push(@val, conversions(1000000, $hz)); - - return @val; -} - -sub outputval($$) -{ - my($name, $val) = @_; - my $csuf; - - if (defined($val)) { - if ($name !~ /SHR/) { - $val = "U64_C($val)"; - } - printf "#define %-23s %s\n", $name.$csuf, $val.$csuf; - } -} - -sub output($@) -{ - my($hz, @val) = @_; - my $pfx, $bit, $suf, $s, $m, $a; - - print "/* Automatically generated by kernel/timeconst.pl */\n"; - print "/* Conversion constants for HZ == $hz */\n"; - print "\n"; - print "#ifndef KERNEL_TIMECONST_H\n"; - print "#define KERNEL_TIMECONST_H\n"; - print "\n"; - - print "#include <linux/param.h>\n"; - print "#include <linux/types.h>\n"; - - print "\n"; - print "#if HZ != $hz\n"; - print "#error \"kernel/timeconst.h has the wrong HZ value!\"\n"; - print "#endif\n"; - print "\n"; - - foreach $pfx ('HZ_TO_MSEC','MSEC_TO_HZ', - 'HZ_TO_USEC','USEC_TO_HZ') { - foreach $bit (32) { - foreach $suf ('MUL', 'ADJ', 'SHR') { - outputval("${pfx}_$suf$bit", shift(@val)); - } - } - foreach $suf ('NUM', 'DEN') { - outputval("${pfx}_$suf", shift(@val)); - } - } - - print "\n"; - print "#endif /* KERNEL_TIMECONST_H */\n"; -} - -# Pretty-print Perl values -sub perlvals(@) { - my $v; - my @l = (); - - foreach $v (@_) { - if (!defined($v)) { - push(@l, 'undef'); - } elsif ($v =~ /^0x/) { - push(@l, "\'".$v."\'"); - } else { - push(@l, $v.''); - } - } - return join(',', @l); -} - -($hz) = @ARGV; - -# Use this to generate the %canned_values structure -if ($hz eq '--can') { - shift(@ARGV); - @hzlist = sort {$a <=> $b} (@ARGV); - - print "# Precomputed values for systems without Math::BigInt\n"; - print "# Generated by:\n"; - print "# timeconst.pl --can ", join(' ', @hzlist), "\n"; - print "\%canned_values = (\n"; - my $pf = "\t"; - foreach $hz (@hzlist) { - my @values = compute_values($hz); - print "$pf$hz => [\n"; - while (scalar(@values)) { - my $bit; - foreach $bit (32) { - my $m = shift(@values); - my $a = shift(@values); - my $s = shift(@values); - print "\t\t", perlvals($m,$a,$s), ",\n"; - } - my $n = shift(@values); - my $d = shift(@values); - print "\t\t", perlvals($n,$d), ",\n"; - } - print "\t]"; - $pf = ', '; - } - print "\n);\n"; -} else { - $hz += 0; # Force to number - if ($hz < 1) { - die "Usage: $0 HZ\n"; - } - - @val = @{$canned_values{$hz}}; - if (!defined(@val)) { - @val = compute_values($hz); - } - output($hz, @val); -} -exit 0; --------------070402000802050303040701 Content-Type: application/x-sh; name="loopy.sh" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="loopy.sh" #!/bin/bash gcc mktimeconst.c || exit 1 X=1 while [ $X -lt 5000 ] do echo $X perl ~/linux/linux/kernel/timeconst.pl $X | sed 's/KERNEL_TIMECONST/__KERNEL_TIMECONST/;/Automatically generated/d;/^$/d'> temp.txt ./a.out $X temp2.txt sed -i '/Automatically generated/d;/^$/d' temp2.txt diff -uw temp.txt temp2.txt || exit 1 X=$(($X+1)) done --------------070402000802050303040701--